Concentration Effects in the Stabilization of PE With a New Natural‐Based Phosphine Antioxidant: Comparison, Reactions, Interactions

ABSTRACT The effect and efficiency of the new, phosphine‐type, natural‐based secondary antioxidant developed recently were compared to those of two other phosphorus stabilizers available on the market. The stabilizers were added to the polymer in amounts changing from 0 to 1000 ppm in 7 steps. The primary, hindered phenolic antioxidant used was Irganox 1010. The efficiency of the stabilizer packages was studied in multiple extrusion experiments following changes in the chemical structure of the polymer, viscosity, color, and residual stability. Component interactions were studied by thermal analysis. The comparison of the various phosphorus stabilizers showed that the efficiency of the new stabilizer is comparable to that of the commercial products. The phosphine rendered the polymer excellent melt stability and very good color. The concentration dependence of properties indicated that about 500 ppm of the secondary antioxidant is sufficient to achieve adequate performance. The phosphine stabilizer interacts synergistically with the hindered phenol primary antioxidant, resulting in the excellent performance observed. The new stabilizer has numerous benefits (natural‐based, good melt stabilization and color), and it can compete with phosphorus secondary antioxidants available on the market.